Smithin K R
Abstract
The successful flight of an aircraft is often attributed to the finesse of its pilots as well as the dispatcher. It is a common practice in air crash investigations to put the blame of such a mishap on the shoulders of its pilots and the air traffic control unit. Most often, the other factors that are inclusive in any successful flight, is omitted. This paper tries to analyze these causes from the perspective of National Transport Safety Board, to generate an independent view about the crash of UPS Flight 1354. After thorough inspection of NTSB reports three main causes for the crash were found 1. Pilots’ lack of experience in maneuvering non-precision approach methods 2. Unavailability of standardized guides and 3. Fatigue issues. All air crash investigations done in the past have found these issues recurring in them. These issues are often easily blamed on the pilots and not addressed thereafter. But strict policy making and enforcement of available regulations still can make a lot of difference in air traffic in the future. Additional regulations that outline a better performance of pilots in non-precision approaches are required. NTSB has included a specific request to have the pilots briefed about the consequences of fatigue prior to flying. Even though these requests are always recurring and recorded, little or no time is usually spent in making them a reality. This accident report is done using the official NTSB report as the primary source.
On August 14, 2013, around 0447 hrs (CDT), UPS Flight 1354, an airbus A300-600, crashed short of runway at Birmingham Airport, Alabama . The official NTSB reports about the crash indicate a mishap with the data entered into Flight Management Computer (FMC) where a discrepancy between the flight plan, as it started from Louisville and as the flight began its descent to the non precision approach runway 18, as the prime reason for the flight’s crash that occurred just shy of making a successful landing.
Summary
UPS Flight 1354 was a cargo flight that had, at the time of its crash, completed 6,800 flight cycles (which is the duration between take off and landing) and 11,000 flight hours. It was scheduled to travel from Louisville International Airport to Birmingham-Shuttlesworth International Airport at 0403 hours. The flight began its journey as scheduled at 0403 hours.
During the course of flight the airmen were informed that the longest runway 06/24 was closed from 0400 to 0500 hours due to runway lighting system maintenance. And since the scheduled landing time of UPS Flight 1354 was 0451 hours, this called for a non precision landing approach onto shorter runway 18 . Non-precision landing approach does not have the support of better navigational guidance schemes that are available for precision landing approaches. It is also called non-ILS (instrument landing system) landing approaches .
The UPS dispatcher informed the flight about the need for non precision landing approach but noticed in the Jeppesen approach chart that non precision localizer approach was not authorized at nights. This made the UPS dispatcher decide to go with non precision area navigation approach.
But the dispatcher did not share this news with the flight crew. This misjudgment resulted from the dispatcher’s belief that the flight crew was aware of this. The data given in the paperwork available with the pilots did not indicate that this was the only approach available for runway 18. In addition to this erroneous performance, the dispatcher did not inform the flight crew about the new forecast cloud ceiling that was calculated as below the minimum descent altitude for RNAV GPS approach.
This might have required the flight to divert to the alternative Harsfield-Jackson Atlanta International airport or wait until the longer runway (06/24) opened. Even though the longer runway was scheduled to open after 0500 hours, the dispatcher did not mention this to the flight crew either. But the flight went in for a descent upon the predication that they (flight crew) might see the airport any minute after they dipped below the minimum descent altitude.
At the Final Approach Fix (FAF) the air traffic controller cleared the flight for localizer 18 approach, upon request from flight crew. The first officer who is responsible for sequencing the FMC with the changed flight plan failed to check for any discontinuities in the data. The new flight plan only included approach fixes. It is important that the FMC is sequenced with new flight data for the FMC to generate valid glideslope (the path of descent for a particular approach). If this is not done without error, the glideslope generated by the FMC shall become useless or erroneous.
But in this incident the captain and the first officer were ignorant to the fact that the direct-to-KBHM waypoint (coordinates to the destination) that had been set in the FMC before the flight began was still remaining in the FMC. This discrepancy in the flight plan data in the FMC caused the glideslope generated for the new profile approach meaningless. And the flight was destined for a disastrous descent.
“Traditional methods of flying non-ILS (non instrumental landing system) approaches involve the using autopilot or vertical-speed modes for the final approach” . But here, since the data in FMC was inconsistent with the new approach fix, it caused the autopilot to fail in fixing a glidepath. Therefore it did not engage in profile mode (the new mode of descent). The captain was forced to switch to vertical-speed mode. But he failed to inform the first officer about this switch .
The confusing that pursued the incident was recorded by the cockpit voice recorder (CVR) where the first officer is seen perplexed of the incident and trying to understand what just happened. But she picked up the update quickly and continued with her job. Since the weather forecast was not given to the pilots, they expected to see the airport any minute after the minimum descent altitude. The first officer as well as the captain continued to watch for the airport as they descended. The first officer is still unaware of the callouts from the FMC stating the inconsistency of the flight plan sequencing.
They continued the descent expecting to see the airport at any moment after they passed the minimum descent altitude at high vertical speeds. But the flight crew failed to spot the airport even after making a major descent depth. The first officer failed to inform the captain about reaching the minimum descent altitude.
At 0447 hours, the CVR recorded the rustling sound of the flight’s contact with trees and a ‘too low terrain’ alert . The recording ended with additional impact noises. Post accident examinations indicated that the flight’s engine had several tree debris stuck in its engines damaging them before the final fire that consumed most of the wreckage.
Contributing factors
The NTSB reports states that the contribution factors included 1. Communication gaps 2. Lack of fatigue awareness and poor off-duty time management from flight crew 3. Lack of standardized guidance 4. Inability to use the altitude alerts available on the flight 5. The final approach technique used.
The NTSB discusses other specific factors for the systemic breakdown of a successful flight 1. The flight crew failed to verify the data in FMC and check for discrepancies 2. The captain failed to communicate to the first officer about the switch he did from autopilot for vertical profile approach 3. The flight crew was not informed of the weather conditions that lead them to believe that they would break out of clouds at 1000ft 4. The captain displayed performance deficiencies which could possibly due to factors such as fatigue, confusion, or his inherent shortcomings that were displayed during trainings 5. First officer was suffering from fatigue from her lack of sleep which could have caused her to ignore various callouts from the inconsistencies in flight plan in the FMC.
Communication gaps between the dispatcher and the flight crew was seriously stated in the NTSB reports. The dispatcher and flight crew did not communicate before the flight take off. The dispatcher also failed to inform the crew about the closing of runway 06/24 and also the weather conditions that made such communications much more essential. The flight crew is also required to speak with dispatch before takeoff but this wasn’t the case in this incident. Neither of them tried to establish communication to check about weather conditions and flight plans.
The flight crew was unaware that the forecast cloud ceiling had stabilized. They were expecting varying cloud ceilings that they continued to descent at high vertical speeds expecting that the airport could be found immediately after the minimum altitude for descent. And their vigilance to locate the airport at high speeds was just another cause of their inability to check the essential flight data such as altitude, proximity warnings, etc. The first officer failed to record that the minimum descent altitude has passed as they were trying to locate the airport.
Even the communication gap between the flight crew members were recorded just before the accident. The first officer was not informed when the captain switched the autopilot to vertical speed mode. The NTSB report notes that “her situational awareness was degraded” due to this. The work load of the first officer was increased due to this lack of awareness. She had to check for flight data in FMC as well as look for the airport in increased vertical speed conditions. The CVR had recorded conversations from the first officer that indicates unawareness and a moment of confusion before continuing her job.
Another important cause given in NTSB report is the lack of fatigue awareness and poor off duty time management. Especially in relation to the first officers failure to sequence the flight plan correctly into the FMC. The NTSB report has repeatedly stated that this task is one of the basic tasks related to piloting a plane. After thorough research the NTSB has confirmed that such lack of concentration from the first officer was attributed to the fatigue she was suffering from. This was concluded after investigating how she managed her off duty time. The first officer was found to have poorly managed her sleep time that had been given to her before the commencement of her flight . This lack of sleep could have resulted in a fatigue that led to her poor performance such as recording and verifying FMC data. Her failure to realize the discontinuity in flight plan couldn’t be blamed on anything else.
But poor off-duty time management was not confined to the first officer. The NTSB investigations reveal that the captain was suffering from fatigue too. Even though captain’s wife had stated nothing unusual about his sleep time management, the inability of him to confirm the flight sequencing, underperformance related to non-precision approach, and carelessness in checking flight data while descending could only be related to fatigue.
Lack of standardized guidance was also found as a major factor that led to this incident. The different guidance tools available with the dispatcher and UPS flight crews were not standardized such that certain precautions, procedures during alerts, etc were not found in each of them . Some of the entries found in PTG (Pilot Training Guide), which is an internal UPS reference manual, were not found in other guides. The errors began when the UPS dispatch concluded that the flight crew was aware of the non precision approach techniques in runway 18 while in fact, the flight crew did not know that localization non precision approach was not authorized during night flights.
One of the other issues was with altitude alerts that are provided within a plane such as EGPWS. Such alerts are required by for terrain awareness of the flight. But FAA has not given any directive to the operators to activate this alert. In this case the UPS failed to activate any such alert that could’ve warned the flight crew about the flight flying too close to the terrain and trees that destroyed the engine and ultimately ended the flight. Even though the NPSB is not certain as to how the flight crew could’ve responded to such warnings, they believe that the flight crew could have adopted go-by round or missed approach to avoid the accident.
The approach technique error has been stated in the report from the beginning. The lack of good guidance for non precision approach makes these approaches much more challenging to the flight crew than it already is. The one issue noted in this accident is that the captain was not that proficient in non precision approach. The errors displayed by the captain in following normal procedures such as the verification of FMC flight plan, etc, was the main reason why the descent could not be completed. It has been noted that the captain had displayed performance shortcomings during the training also .
Above all, both the crew members were found to be distracted from the main course of events during the flight. The cockpit recorder had recorded some of their lighthearted comments about the runway 6 being closed. The captain is responsible for keeping decorum in the flight. The procedures to be followed during takeoff and landing was not followed in this particular incident. The crew was found to be a little concerned about the closing of runway 6. The captain and the first officer were engaged in some light conversations about it throughout (recorded by the CVR). The author of the report has indicated that some of the basic things like sequencing of the flight plan in the FMC were missed due to the interruptions and distractions in the cockpit .
“The National Transportation Safety Board determines that the probable cause of this accident was the flight crew’s continuation of an unstabilized approach and their failure to monitor the aircraft’s altitude during the approach, which led to an inadvertent descent below the minimum approach altitude and subsequently into terrain” .
Recommendations
The NTSB reports concluded that a number of contributing factors were responsible for the ultimate demise of UPS Flight 1354. As per the flight crash reports it is evident that of these factors most of them could’ve been avoided by a prompt procedural performance of the flight crew, dispatch unit, and strictly following regulations.
Better communicative training for members in dispatch: In the light of this incident, after conducting many investigations, NTSB found that the UPS dispatcher involved in the accident, was reluctant to speak to the pilots before the commencement of the flight. His reluctance in establishing communication with the crew was the reason why they was not informed of the weather conditions, closing of runway 06/24, and the problem of using a localizing non precision approach during night time. It was reported that he said that he usually preferred not to disturb the pilots for non-significant information. According to FAA regulations, the pilots are required to communicate with the dispatch at the destination airport. They are supposed to ask about weather, runway conditions, etc. But in this case, the airmen had no knowledge of the changes in destination airport. They were briefed about this just before landing time.
Better and strict fatigue mitigation regulations: The final report on the crash indicated that the first officer was suffering from tiredness and fatigue due to her poor management of off-duty time. The report also mentions that the captain could’ve been suffering from a similar plight. The performance deficiencies of both pilots were primarily blamed on their fatigue by the report.
It is said that the first officer did not use her sleep times of previous day or night enough to be relieved of normal circadian rhythm. Even though it was in regulations that flight crew should report their tiredness, the first officer did not. It is highly recommended that fatigue mitigation regulations should be formulated such that they would strictly check the future occurrences of such incidents. The NTSB report recommends the use of fatigue awareness classes to help the pilots realize the importance of reporting their state of mind before flight. According to FAA regulation, pilots are required to verify whether they are fit to fly the plane. If not, they will be provided time to recover before they could fly again. This rule was not followed in this incident.
Improve proficiency in non precision approaches: A better and effective group of navigational guidance systems are available for precision approach to make the descent easier for the pilot. The absence of such help in non precision approach usually deters pilots from using this during their normal flight. In this incident, the captain was completely unaware of the procedures to be followed before a non-precision approach. The captain did not ask the first officer to verify the flight plan sequencing (as per procedure). He also forgot to check the FMC callouts during his attempts to locate the airport visually. It has been found that he was unaware of the need of using missed approaches or fly-by method during such cases.
The lack of practice makes pilots dull in non-precision approach as it lacks in navigational guidance. It is recommended by NTSB that the pilots should be restrained from using autopilot or navigational tools under normal conditions such that their non precision approaches are improved. The NTSB stresses particularly on the need for FAA regulations to check this.
Better maintenance of ground proximity warning system and alerts: The report of NTSB claimed that the proximity warning system used in the accident was not up to date. The EGPWS version available at the time of the accident was capable of providing warning almost 6.5 seconds earlier than the one working in UPS flight 1354.It is recommended that Air craft maintenance crews should make sure that all the warning systems in every flight is up to date and working properly.
Better weather report dissemination: The flight crew of UPS flight 1354 was not updated of the weather conditions at the destination. The beginning of the descent was flawed due to their wrong judgment of weather conditions. The weather report they were provided was based on the data obtained prior to the commencement of flight. This report stated that the weather was unstable and the forecast cloud ceiling was somewhere below the minimum descent altitude. This report was later updated with a stable cloud ceiling and consistent weather conditions. The crew was keen on finding the airport visually after they began the descent according to the original weather report. But this attempt failed as the cloud ceiling was different at the time of descent. The crew, owing to their carelessness in realizing that the minimum descent altitude has passes, still continued the descent to visually locate the airport.
This could have been avoided if the flight crew was provided updated weather forecast during the flight. Even though the dispatch aware of this, they did not take the time to warn the crew. The NTSB report suggests that weather data provision should be mandatory during a flight.
Standardization of guides: In this particular case, the lack of standardized guides was proved to be a menace to the crew as well as the dispatch. The use of localizer non-precision approach was not recommended during night flights. But the crew was not aware of this. The dispatch believed that the guide provided to the flight crew contained this information. To avoid further conflicts between flight crews and dispatch in terms of knowledge about descent approaches, a standardization of guides should be noted. The NTSB report recommends the use of a single standardized guide to be in the possession of the dispatch and flight crew.
References
NTSB. (2014). Crash During a Nighttime Non precision Instrument Approach to Landing UPS flight 1354. Washington: National Transportation Safety Board.
Tarnowski, E. (2007, October). Non-precison approaches to precision like approach. Retrieved Janurary 29, 2016, from FlightSafety: http://flightsafety.org/asw/oct07/precision_approaches_web.pdf?dl=1
